| AVS 63rd International Symposium & Exhibition | |
| Applied Surface Science | Wednesday Sessions |
| Session AS+SS-WeM |
| Session: | Applications where Surface Analysis is Your Only Hope |
| Presenter: | Taraneh Bozorgzad Moghim, University of Surrey, UK |
| Authors: | T. Bozorgzad Moghim, University of Surrey, UK M.L. Abel, University of Surrey, UK J.F. Watts, University of Surrey, UK |
| Correspondent: | Click to Email |
Aircraft coatings are subjected to a multitude of environments during their service life time, including high humidity, extreme temperatures and solar radiation. The major source of degradation derives from ultra-violet (UV) radiation. With commercial aircrafts flying at altitudes between 9 and 13 km, their exposure to UV radiation and ozone significantly increases. Therefore photooxidation of an aircraft topcoat must be understood in order to monitor topcoat degradation. The main laboratory technique used to establish the degradation phenomena from UV radiation is through QUV chambers, however the effect of ozone is not considered in this method. The novelty of the approach used here, is in the use of a desktop cleaner, intended for SEM sample preparation, as the exposure method. This combines the effects of UV and ozone. The topcoat was subject to UV/ozone exposure for varying durations and analysed using time of flight-secondary ion mass spectrometry (ToF-SIMS).
The detail provided by ToF-SIMS is vital in understanding the degradation phenomena and enables a degradation mechanism to be established. ToF-SIMS produces a significant amount of data and therefore when combined with principal component analysis (PCA) a more detailed analysis of the data can be obtained. The main changes observed are the rise of inorganic components with exposure time, as the polymer resin decomposes and the inorganic pigments of the coating are exposed. However this does not describe the degradation of the organic components. Therefore by filtering out the inorganic contributions in the PCA, the changes to the organic components could be isolated and observed. This allows the positive identification of cluster ions of the reactants from the resin and those from the reaction products. In this manner it was possible to deduce the degradation mechanism.